Flowerpot project

Over 50% of Sydney's natural foreshore has been replaced by seawalls to protect the city's infrastructure. Due to expanding development and sea level rise, th﻿is number is only going to increase in the future. This is a problem for marine life as seawalls and other artificial structures, like pilings and breakwaters, don't contain many of the different homes that animals need to live, for example crevices, rock pools and boulders. This is one reason why seawalls have significantly fewer marine species living on them in comparison to a natural rocky shore.

To sustain marine life in Sydney harbour, researchers in collaboration with engineers, councils and other managers are exploring ways to redesign artificial structures to be more ecologically friendly, whilst still maintaining the primary role of coastal defence. This can be achieved relatively simply, by incorporating different habitats into the artificial structures, rather than the structures being vertical and flat.

One way that researchers at the University of Sydney are using to increase the biodiversity of seawalls in the harbour are 'flowerpots'. These marine pots are attached to the seawall, are submerged during high tide, and retain water at low tide, introducing a rock pool habitat to the wall. Rock pools are important for many species as they provide a refuge at low tide. Sydney harbour's marine life seem to love these new homes, with 21 new species living in the pots in comparison to the seawall after 7 months of installation.